Process for manufacturing ar-tetrahydronaphthols and their esters



Patented May 17, 1932 UNITED STATES.

PATENT OFFICE ERNST KORTEN, F FEGHENHEIM, NEAR FRANKFORT-ON-THE-MAIN, GERMANY, AS-

SIGNOB, TO I. G. FARBENIND-USTRIE AK'I'IENGESELLSGHAFT, OF THE-IVIAIN, GERMANY, A CORPORATION OF GERMANY. l p y PROCESS non MANUFACTURING Aa-TETRAnYnRoNAPHTHons AND THEIR nsrnns No Drawing. Application filed November 19, 1928, Serial No. 320,540, and in Germany November 21, 1927.

The present invention relates to a process of manufacturing ar-tetrahydronaphthols and their esters and to the new ar-tetrahydronaphthol esters obtainable thereby.

I have found that by treating naphtholesters of the general formula:

X wherein X stands for hydrogen or a monovalent substituent, with hydrogen in the presence of a base metal hydrogenation catalyst in a smooth reaction and practically without the formation of by-products ar-tetrahydronaphtholesters are obtained Corresponding to the general formula 2 H2 wherein X stands for hydrogen or a mono valent substituent. The result of this process is a most unexpected one, because generally, when directly hydrogenating naphthols, the nucleus containing the hydroXy group is hydrogenated, and on the other hand, when hydrogenating in presence of a noble metal hydrogenation catalyst, entirely hydrogenated products are obtained. My process of hydrogenation is advantageously carried out in the presence of an organic diluent. When saponifying the ar-tetrahydronaphtholesters obtained according to my process in the usual manner, the corresponding artetrahydronaphthols of the general formula:

Hi wherein X stands for hydrogen or a monovalent substituent, are obtained.

The ar-tetrahydronaphtholesters as well as 4 I E trampled] 1.00 parts of I pure acetic acid-a-naphthyl ester of the formula f Y O-OO-CH:

are treated with 2 parts of a nickel containing catalyst previously reduced by 'means of FRANKFORT-ON- hydrogen, under a hydro-gen pressure of 30 80 atmospheres while well stirring-The absorption of hydrogen already begins below 100. At the end of the reaction the temperature is advantageouslyraised to about 110. When an amount of hydrogen corresponding to 2 molecules is absorbed, the reaction product is separated from the catalyst while still warm and distilled in vacuo. first-runnings have passed over, the mainproduct distills at 142-144 under a pressure of 10 mm. It is the new acetate of ar-lhydroxy-tetrahydronaphthalene of the formula H2 It has the form of snowewhite crystals melt- When warmed with a dilute caustic soda solution, it dissolyes. after a short time because of being saponified. From the colorless solution the sodium saltof ar-l-hydrox'ytetra-hydronaphthalene separates in' snow- After small White crystals. By acidifying, the free ar-lhydroxy-tetrahydronaphthalene of the formula is obtained. It meltsat about 68-*'-as described in vLiebigs Annalen,vo1. 426, page Emample? 3 formula When acetic acid-fl-naphthylester of the is. treated according to Example 1, ar-2- hydroxy -'tetrahydronaphthalene and its acetic 'acidester areobtained both of which compounds are already described in Liebigs Annalen, vol. 426, page 119.

Examples? When in Ex-amzple l the acetic acid ester'of a-naphthol is replaced by the corresponding benzoic acid ester of the formula:

the new benzoic acid ester ofar-l-hydroxytetrahydronaphthalene is obtained in a smooth. reaction. It corresponds to the formula: V V

7 Hz and crystallizes from benzine or methylalcohol in small brilliant tablets melting at about 46.

By saponifying, it yields ar-l-hydroxytetrahydronaphthalene. I Example 4 150 parts of the acetic acid ester of the 2- hydrOxy-S-naphthoic acid methylester of the formula:

' o oo-oH;

100 parts of decahydro-naphthalene and 2.5 parts of a catalyst containing nickel and pum ice are heated to 100-110 in an autoclave provided With a stirrer, While introducing hydrogen. The absorption of hydrogen occurs very smoothly at30-50 atmospheres and is stopped, When 2 molecules are taken up. The

new acetic acid ester of ar-2-hydroxy-tetrahydronaphthalene3-carboxylic-acid methylester thus obtained, corresponding to the for: mula: v

o oo or[ H2. 3

crystallizes from benzine, dilute meth 1 al-' cohol or dilute acetic acid in White bri liant needles melting at about 94? and boils undera pressure of 5 mm. at about 193.- 1

It yields, When saponified, the 2-hydroxyar-tetrahydro-naphthal'ene-3 carboxylic acid of the formula:

I fHz i H --ooon Iii melting at about 176 as described in Annalen, vol. 426, page 147. a

Example 5 parts of the acetic acid ester of 2-hydroXy-3-naphthoic acid ethyl-ester, 50 parts of decahydro-naphthalene and 2 parts of a Liebigs reduced catalyst containing nickel, kieseldroxy tetrahydronaphthalene- 3- carboxylic' acid as described in Example}. I v

. Also other nuclear substitution products of naphtholesters such as 1.2-carbonyl-amiuo-naphthol (Journal fiir prakt. Chemie, Vol.-

92, page 2581) may be subjected to thesame 2 process, yielding correspondingly hydrogenated products.

E wample 6' 80 parts of the carbonic acid ester of 0cnaphthol corresponding to the formula:

leaflets melting .10- parts of deca-hydronaphthalene and 1.2 parts of a reduced catalyst containingnickel and pumice are stirred in an autoclave under a hydrogen pressure of -30 atmospheres. The absorption of hydrogen begins at about and is stopped when the amount calculated for 4 molecules is introduced. The reaction mass is Worked up as described in the foregoing examples. The new carbonic acid ester of 1-hydroxy-ar-tetrahydronaphthalene of the formula:

I H, o--ooo 7 corresponds to the formula:

as r o o and crystallizes from benzine, methylalcohol or-glacial acetic acid in small colorless flat at about 106.

Example 8 The acetic acid ester of 1-methyl-2-hydroxy-naphthalene of the formula:

of 66 melting point (see Berichte der deutsch. chem. Gesellschaft, vol. 39, page 442) is hydrogenated as described in Example 1. The reaction product is worked up by filtration and distillation in vacuo. Themain fraction boils under a pressure of 9 mm. at about 156. It represents the new acetic acid ester of ar-Lmethyl-Q-hydroxy tetrahydronaphe thalene of the formula Hi I and shows nearly the same properties asthe product described in Example 2.

I claim:

1. A process which comprises treating naphthol esters of the general formula:

wherein X stands for hydrogen, an alkyl group or a carboxylic ester group, with hydrogen, under supera'tmospheric pressures and at temperatures between about room tem-' perature to aboutllO C. in the presence of a base metal hydrogenation catalyst. v 2. A process which comprises treating naphthol esters of the general formula:

wherein X stands for hydrogen, an alkyl group or a carboxylic ester group, with hydrogen, under superatmospheric pressures and at temperatures between about room temperature to about 110C. in thepresence .ofa base 'metal hydrogenation catalyst with the addition of an organic diluent.

3. A process which comprises treating naphthol esters of. the generalformula:

wherein X stands for hydrogen, an alkyl 1 group or a carboxylicester group, with hydrogen, under pressures between about 20 to about 80 atmospheres and at temperatures between about room temperature to about C. in the presence of a base metal hydrogenation catalyst.

4. A process which comprises treating naphthol esters of the general formula:

0-acyl wherein 'X stands for hydrogen, an alkyl group or a carboxylic ester group, Withh drogen, under pressures between about 20 to about 80 atmospheres and at temperatures between about room temperature to about 110 C. in the'presence of a base metal hydrogenation catalyst with the' addition of an organic diluent.

;5. A process which comprises treating naphthol esters of the general formula;

O- acyl wherein X stands for hydrogen, an alkyl group or a carboxylic ester group, with hydrogen, ,under pressures between about 20 to about 80 atmospheres and at temperatures between about-zroom temperature to about 110 C. in the presence of a base metal hydrogenationcatalyst.

6. A process which comprises. treating naphthol estersvojf the general formula:

wherein X stands for hydrogen, an alkyl group or a carboxylic ester group, with hydrogen, under super-atmospheric pressures and at temperatures between about room temperature to about 110 C. in thepresence of a base metal hydrogenation catalyst, and saponifying the hydroxy-ar-tetra-hydronaphthaleneestersthus formed of the general formula: v

H2 wherein X stands for hydrogen, an alkyl group or a carboxylic ester group.

'7. A process which comprises treating naphthol esters of the general formula:

wherein X stands for hydrogen, an alkyl group or a carboxylic ester group, with hydrogen, under superatmosp'heric pressures and at temperatures between about room temperature to about 110 C. in thepresence of a base metal hydrogenation catalyst with the addition of an organic diluent, and saponitying the hydroxy-ar-tetra-hydronaphthalene esters thus formed of the general formula:

wherein X stands for hydrogen, an :alk-yl group-or a carboxylio ester group.

8. .A process which comprises treating naphthol esters of the general formula:

wherein X stands for hydrogeln angalkyl group or a carboxylic ester group, with hydrogen, under pressures between about 20 to about 80 atmospheres and at temperatures between about room temperature to about 110 C. in the presence of a base metal hydrogenation catalyst andsaponi'fying the hydroXy-ar-tetra-hydronaphthalene esters thus formed of the general formula:

wherein X stands for hydrogen, an alkyl group or a carboxylic ester group] 9. A process which comprlses treating naphthol esters of the general formula.:.

O acyl wherein X stands for hydrogen, an alkyl group ora carboxylic ester group, with hy- A drogen, under pressures between about 20 to about 80 atmospheresand at temperatures between about room temperature to about 110 C. in the presenoeof a base metal hydrogenation catalyst with the addition of an organic diluent and saponifying the hydroxy-artetra-hydronaphthalene esters thus formed of the general formula:

wherein X stands for hydrogen, an alkyl group or a carboxylic ester group, with hydrogen, under pressures between about 20 to about atmospheres and at temperatures between about room temperature to about C. in the presence of a base metal hydrogenation catalyst and saponifying the hydoxy-artetra-hydronaphthalene esters thus formed of the general formula:

III: 0acyl H:

wherein X stands for hydrogen, an alkyl group or a carboxylic ester group.

11. As new compounds the l-hydroxy-artetrahydro-naphthalene esters corresponding to the general formula:

which compounds are colorless crystallized substances having a definite melting point, soluble in organic solvents, insoluble in water, capable of being saponified to l-hydroxyar-tetrahydronaphthalene.

12. As a new compound, the acetate of ar- 1-hydroxy-tetrahydronaphthalene of the formula:

H1 O-O O-GH:

representing in a pure state snow-white crystals melting at 7 3 to 75 C.

13. As a new compound, the benzoic acid ester of ar-l-hydroxy-tetrahydronaphthalene of the formula:

crystallizing from benzine or methyl alcohol in small brilliant tablets melting at about 46 C.

In testimony whereof I aflixmy signature.

ERNST KORTEN. 

